1. Field of the Invention
The present invention relates generally to a storage system, and particularly to coupling and splitting of a module-type storage system. The invention also relates to a storage system management method.
2. Description of Related Art
In, for example, a database system that handles large-scale data such as on used in a data center, data is managed by using a storage system separate from a host computer. This storage system is composed of, for example, a disk array apparatus. The disk array apparatus can provide the host computer with logical volumes (logical units) formed in storage areas in a plurality of storage devices in response to input/output requests from the host computer.
In a storage system where a disk array apparatus is connected via a communication network to a host computer, the storage system is logically split in accordance with changes in the system configuration (see U.S. Pat. No. 7,069,408).
The above-mentioned function of logically splitting the storage system is based on the premise that storage systems, which are split in one apparatus, are defined and, for example, unused resources (unused disks) are allocated to and used in each split storage system. In other words, no consideration is given to the operation scenario where the storage system is physically split and, as a result, data will be migrated or control information will be split. Also, the possibility of dynamically (online) coupling a plurality of storage housings to each other and operating and managing them as a single storage system is not assumed.